Goal:
    A : Type  HA : ReflectEq A  x : option A  y : option A
  ============================
   (reflectProp (x = y) (eq_option eqb x y))


DEBUG:Going to execute:
<coq-core.plugins.ltac::unify@0> $1 $2
DEBUG LTAC Evaluated term: Type
DEBUG LTAC Evaluated term: (ReflectEq A)